Xeris pallicoxae

Formally conflated under Xeris spectrum, all British specimens in the British Museum of Natural History, were found to be Xeris pallicoxae by Goulet et al in 2015. In pallicoxae the yellowish-white band on the pronotal shoulders is largely smooth between raised peaks, whereas in spectrum the bands are heavily ridged. In lateral view the pronotum of pallicoxae has only sparse pits, whilst spectrum has numerous coarse pits over at least one third of the area such that the margins form raised reticulation.

The females have light reddish brown coxae (black at least on the outer face in spectrum).

The male has a large yellowish-white spot, quite sharply outlined, extending to the genal carina but not behind onto the occiput. The hind femur is reddish-brown to black. The hind basal tarsal segment is narrowly reddish-brown and in most cases the second tarsal segment is banded with black centrally.

Xeris pallicoxae larvae feed in the timber of coniferous trees and take 1 to 3 years to emerge.

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Size: 15 - 30mm (excl. ovipositor)

Status: Rarely encountered

Distribution: England, Wales, Ireland

Flight period: June to October

Plant associations: Pinaceae (coniferous trees) (1)

Larix spp. (larches) (2)
Abies alba (European silver-fir) (2)
Abies cilicica (Cilician fir) (2)
Picea abies (Norway spruce) (2)
Pinus radiata (Monterey pine) (2)

The National Biodiversity Network records are shown on the map below. (See terms and conditions)

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References:

1. Benson, R.B., 1952. Handbooks for the Identification of British Insects. Hymenoptera, Symphyta, Vol 6, Section 2(a-c), Royal Entomological Society, London

2. Goulet, H., Boudreault, C. and Schiff, N.M., 2015. Revision of the world species of Xeris Costa (Hymenoptera: Siricidae). Canadian Journal of Arthropod Identification, 28.